The present invention is generally directed to a carrier apparatus for a pneumatic tube delivery system. More specifically, the subject carrier apparatus is one which safely and securely transports various items through the tubular conduits of a given pneumatic tube delivery system. The subject carrier apparatus provides simple yet durable structure that facilitates safe, convenient handling and use.
Pneumatic tube delivery systems are widely used in various institutions. The system is implemented in different forms depending on the nature of the operations and transactions carried out at a particular facility. Nonetheless, the systems invariably share certain basic components. First, a network of tubular conduits is established throughout the facility, branching out to various user outlets connected to respective send/receive workstations, or portals. Items of interest are then transported between user outlets via the network of delivery tubes by a capsule-like carrier, the contents of which are filled by a user at an originating outlet and emptied by a user at a receiving outlet. The carrier's travel through the network of tubular conduits is driven by one or more blower units which generate sufficient pneumatic flow (such as by vacuum pressure) to propel various capsules through different portions of the network. Typically, a computer-based controller unit(s) operates to regulate carrier traffic and maintain overall system operation.
The network of tubular conduits can become quite complex even in modest sized facilities, since delivery access between all combinations of user outlets is often required. The network generally incorporates multi-port diverters, or transfer units, at certain intermediate points in the network. These units operate to physically transfer a carrier from one branch (or section) of the tubular conduit network to another for delivery to the proper destination outlet. While such diverter/transfer units markedly reduce redundancy in conduit segments, the network remains quite elaborate in systems serving numerous outlets, with individual conduit segments making numerous turns and bends to serve the many user outlets.
Among the institutions that employ pneumatic tube delivery systems are financial institutions such as banks which use the systems to remotely conduct customer transactions in real time. Others include industrial and retail facilities where payload items like documents, currency, parts, or merchandise are transported from one location to another. Perhaps the most prevalent and demanding uses may be in healthcare institutions like hospitals, where the need for quick and efficient physical transport of items between remote locations within the facility tend to be the rule, not the exception. Items such as pharmaceuticals, lab specimens, blood products, and the like must be passed between different staff members quickly and reliably. It is not uncommon for hospitals to carry out several thousands of transports for delicate payloads like this on a daily basis.
There are numerous challenges to maintaining efficient operation of pneumatic tube delivery systems, especially those deployed in such heavy-use, critical settings. A number of notable challenges pertain to the structure and form of the carrier employed in the system. Since each and every transport necessarily involves a carrier, it is imperative that the carrier be viable in structure. At a minimum, it must be wide enough to substantially ‘plug’ the tubular delivery conduit segments for pneumatic propulsion therethrough, yet streamlined enough to negotiate all the turns, bends, and other transition points in the tubular conduit network smoothly, and without getting ‘stuck’ inside. Were a carrier to become stuck somewhere in the network, the great labyrinth of tubular conduits and transitional hardware deployed in many facilities make it a major effort to precisely locate and free the carrier. While a stuck carrier is sometimes extracted by manually operating a blower to either push or pull the carrier free, it can mean at least a partial shutdown of the system for an extended period. In that event, technicians would need ample time to carry out the tedious task of first locating the stuck carrier, then accessing the carrier by disassembling or even cutting the conduit segment in question, before restoring the conduit segment for use upon extrication of the carrier.
Reliably ensuring that the carriers are properly closed for transport is another constant challenge. Because the carrier travels through confined spaces at high speeds, being all the while subject to forceful impact and abrupt changes of direction, there is much to potentially disturb and jar a carrier's closure mechanism loose. For example, the snap-buckle type latching mechanisms used in many carriers heretofore known are prone to spring free when acute incidental contact or a sudden shift in direction disrupt and overcome the mechanism's closure bias. Intervening hardware like transitional/diverter units also present potential snag hazards for such latching mechanisms.
Just as important as keeping a carrier's closure mechanism secure during transport is ensuring that the carrier is properly closed and latched in the first place. Numerous latch mechanisms known in the art may have a closure mechanism that has failed to actually latch the carrier shut, yet appear properly latched to a busy user upon quick (or distracted) glance. The need for a mechanism which effectively guards against such false closure, or which at least makes a false closure conspicuously evident, cannot be understated.
Other challenges derive from the fact that the oft-used carrier must be versatile enough to carry a wide range of payloads. Since their maximum transverse (diametric) dimension is limited by the conduit size employed in the given system, carriers in most systems are necessarily elongated and bulky in form. Yet, their high speed travel through confining tubular conduits precludes the use of external handle attachments to facilitate handling. Consequently, carriers heretofore known in the art tend to be difficult to firmly grasp and safely manipulate with one hand. This is not a trivial hindrance, particularly in critical settings such as hospitals, where carriers are very often loaded with sensitive, delicate payloads like lab specimens and pharmaceuticals, and where use is frequently made amidst pressures to meet patient care needs.
Users in these settings can ill afford to mishandle carriers. Nor can they afford the risks of the carriers tipping or rolling away (and perhaps off a table surface) when they are momentarily set aside during user handling. Yet no adequate safeguard measures are provided by carriers heretofore known in the art.
Still another challenge to efficient, reliable system operation is the carriers' general durability in the face of daily repetitive use. In addition to the normal incidental contact encountered during travel through the conduit network and mechanical handling such as at intervening transfer points, carriers typically encounter sharp impact each time they arrive at their destinations. On arrival, the pneumatic flow pressure is cut off and the carrier deposits onto the destination outlet's receiving plate, where it is released and abruptly dropped onto a receiving pad surface. The shock of this impact, especially when repeated over and again with regular use, wears on the carrier and potentially leads to premature stress failure over time at its axial ends and elsewhere.
To enable sufficient air-seal, reduce friction, and provide cushioning as they move through the tubular conduit, carriers typically employ a fabric or brush band typically referred to as a glide-band or wear-band around its circumference. Over time and with repeated use, glide bands become worn down causing their friction reducing and cushioning properties to diminish. At such time, the bands must be replaced. Many carriers known in the art have the band directly attached to the carrier body with adhesive, with some also using a mechanical fastener in addition to an adhesive. This approach makes later removal of the bands for replacement difficult since the adhesive, in order to maintain attachment to the carrier during transport, must be very strong.
These and other challenges are not adequately met by carriers heretofore known in the art. Hence, there is a need for a secure and durable carrier apparatus capable of unencumbered transport through a pneumatic tube delivery system. There remains also a need for a carrier apparatus whose structure preserves reliable payload containment and affords sure, convenient handling by users.